The skin is delicately affected by aging, and external environments such as temperature, humidity and ultraviolet rays, etc. Therefore, the decrement of various functions of the skin, and aging of the skin are brought about, and various troubles such as wrinkling and skin roughness occur. In order to improve these cutaneous troubles, it has been attempted to incorporate various components having a skin roughness-improving effect and an anti-aging effect, such as synthetic or natural moisturizing components, natural extracts such as sesame oil, rutin sugar derivatives, proteins such as sericin, and α-hydroxy acids into external skin care compositions such as cosmetic compositions.
For example, polyhydric alcohols such as glycerol and propylene glycol; saccharides such as sorbitol and maltitol; amino acids; polymeric substances such as hyaluronic acid and chondroitin sulfate; etc. are known as the moisturizing components. However, the use of these moisturizing agents involves a problem that a sticky feel is given users.
The present applicant found and discloses that a lamellar structure comprising a fatty acid monoglyceride as a main component has a high moisturizing effect (Japanese Patent Registration No. 2606761). However, occurrence of foaming is unavoidable in the production of this lamellar structure, which becomes a problem from the viewpoint of production efficiency. In addition, there may be offered a problem that a part of the lamellar structure is destroyed according to conditions of storage.
Japanese Patent Application Laid-Open No. 500355/1989 through PCT route discloses a method for preventing or improving changes or damages of the skin due to skin aging and/or exposure to sunlight by incorporating vitamin A or a derivative thereof. However, vitamin A is insufficient in effects of improving skin roughness and suppressing wrinkling and also involves a problem that it forms the cause of offensive smell and stickiness.
It is therefore an object of the present invention to provide a skin preparation for external use which has high effects of improving skin roughness and suppressing wrinkling, etc., shows neither any offensive smell nor stickiness, and exhibits controlled foaming upon production thereof.